[vetsen]

I have been doing more 3D modeling in BC lately, and have run into a problem doing a sweep.

The first curve (cross section) is perpendicular to the contour, but the resulting solid is on an angle for some reason.





BOBcad File V23
https://dl.dropbox.com/u/82376106/test-sweep.bbcd


Any ideas?

Steven

[BurrMan]

Go to your profile and delete the .05 fillets and use utilities-trim extend-two entities and connect them to a rectangle again. Then run your sweep and run a .05 fillet on the resulting part.

[vetsen]

Thanks Burrman,

I will give that a try, but doesn't it seem like it should be able to do the sweep with any geometry? Why only a rectangle?

Steven.

[BurrMan]

but doesn't it seem like it should be able to do the sweep with any geometry? Why only a rectangle?

Well, yes and no.

Although this sweep is fairly simplistic, BobCads sweep command is fairly simplistic.

A basic rule in modeling is putting little radius' and detail on "after" or later in the process. Trying to make little radius' sweep around in 3d space makes the command more complex by nature. The command has to make a determination of profile orientation as it sweeps along in 3d space in relation to the path. The little radius' are throwing off the orientations autoplace, which for BobCads sweep command, is simplistic, as it is non-controllable.

Although we should expect this case to produce a result.

Following the simple rule will get you results, even with BobCads simplistic sweep. It will also be good for you to "train yourself" with this knowledge. It will help you even with more high end modeling packages to know the basics.

[BurrMan]

So here's another way to make it work, considering the autoplace mechanism.

Placing your profile within the bounds of the path, has it take orientation consideration from the path. (Here you also need to remember that BobCad works mostly in a single UCS "paper space". Note your profile and path are not on it)

If you re-orient your profile and path to be on the active UCS, and also "seperate" from each other, then the autoplace mechanism will make a more intelligent decision as to the sweep. Then you can orient the result to somewhere in space after you have an object.



So, attach to the top center of the profile, then chain select just next to it, then chain select your path at the end.

This allows the auto place to work and you can rotate and translate the result into position. Example file attached.